RAR archive of 489 KB labelled X99-A, with no brand, document type or revision in the name. The title suggests material for a board on the Intel X99 chipset, but the contents are not described and should be checked after extraction. A file of this size more often holds a boardview or schematic than a complete firmware image. Confirm the model and revision silkscreened on the PCB match before using it to locate parts, trace power rails or look for a shorted circuit.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @boardview. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
7-ZipWinRARThe Unarchiver (macOS)